The present invention relates generally to pumps, and more particularly to a bearing carrier for such pumps that use multiple lubrication access locations for bearings located within the pump.
Chemical process pumps are often used to move petroleum products, industrial chemicals, solvents and related fluids. Such pumps are especially well-suited for use with low-viscosity and relatively non-abrasive fluids. In one particular form, chemical process pumps employ rotating vanes that are placed relative to complementary stator or related housing surfaces to ensure tight tolerances and precise degrees of adjustment. One form of such pump, which is manufactured by the assignee of the present invention, is a centrifugal pump with a rotating impeller; such pump is referred to commercially as the Flowserve Durco® Mark 3™ ISO Pump.
For optimum capability for handing chemical products, the impellers of such pumps are of a semi front-open type, or a reverse vane type. To ensure continued proper operation over time, the pump impeller may need to be periodically adjusted. In such case (as with the pump model discussed above), the pump may include a device to permit fine-tuned adjustment of the impeller. Such a device involves rotating a bearing carrier that is disposed within a bearing housing; such a process is referred to by the Assignee of the present invention as “micrometer adjustment”. While this ability to quickly and precisely adjust impeller clearances significantly contributes to overall pump operability and efficiency, it increases the complexity of the mechanism used to contain the pump's thrust bearings. This is especially true in situations involving bearing lubrication, where the connection for grease lubrication or oil mist is traditionally situated in the end face of the bearing carrier to give a simple direct passage into the chamber behind the bearing. This connection position has two disadvantages. Firstly (in situations where the connection is configured to receive grease), the connection is inside a coupling guard which therefore has to be removed every time re-greasing is required. Secondly (in situations where the lubrication system is oil mist), because the bearing carrier is rotatable, then the piping carrying the oil mist to the connection on the bearing carrier has to be remade each time the micrometer adjustment is used. In either form, this undesirably increases maintenance time and complexity.